The subject matter disclosed herein relates to tolerance testing components.
The various components of a system, such as a rotor stub shaft, for example, often must be individually tolerance tested prior to their incorporation into the system. Specifically, various elements of the component may be checked individually for form control (e.g., circularity for a diameter, flatness for a planar surface) and also to ensure that the relative location of elements (e.g., eccentricity for a diameter) is within required tolerances. In many cases this tolerance testing requires multiple set up operations of a probing tool. For example, when a shaft is tested, different sets of measurements (circumferential and axial) are taken to determine parameters such as circularity and eccentricity each time the shaft is set up for probing to determine relative variations of different elements of the shaft. Each set of these measurements is taken by setting the part in a lathe and rotating or moving the shaft while measuring an offset (run out) of one or more probes from their initial positions. This method of measurement is prone to false positive or false negative results based on how the lathe is positioned within the shaft during the measurements. That is, for example, if the shaft is not centered within the lathe, the probe may experience offsets due to the wobble created by rotation on the un-centered shaft rather than due to variations in the form and location of the shaft. In addition, the specific verification of relative location of different parts (elements) of the shaft requires a different setup (positioning of the lathe) for each such verification.